Today I installed Tunelab to that LG phone. Does not work properly! One problem: after opening the tuning curve the audio input is gone.
This sounds like a hardware fault. The audio input should always be active (unless you switch to generating tones).
I didnÂ´t change anything in the tuning curve settings (set to automatic). Then I tuned the temperament octave and the result was awful. The octave A4-A3 was to wide...
What tuning file were you using? One of the packaged files that comes with TuneLab? Or did you make a custom one?
Then I changed from 6:3 to 4:2 and A4-A3 was much better..
6:3 in the bass gives a very conservative stretch. 4:2 gives an even smaller stretch. If 6:3 in the bass gave you too much stretch, then it is likely you were using some bad inharmonicity readings. You can diagnose many such problems by looking at the tuning curve and seeing what the offset is at A0 and C8.
But from what you have said about the audio stopping, it is questionable whether you have a working system. If the audio input is stopping, then I would not trust any other result that came from that phone until I had verified it with more primitive operations.
There is nothing inherently wrong with phones without AGC. Just watch the volume indicator in TuneLab to check that it is not overloading. You should be able to get proper operation with volume levels between 20% and 99% of full scale.